Some heavy duty trucks assemblies include, in combination, a tractor and one or more trailers joined in series to the rear portion of the tractor. The trailer usually is equipped with various electrical systems, such as brake lights, turning signal lights, and anti-lock braking systems. These electrical systems in the trailer are typically powered by the electrical system of the tractor. To establish an electrical connection between the tractor and the trailer, an electrical cable is connected between the rear wall of the tractor and the front wall of the trailer. Similar connections can also be made between trailers if the truck assembly includes more than one trailer.
Each of the electrical cables typically has a suitable plug configured to connect to a cooperating socket. The socket is generally mounted on the rear wall of a tractor cab or the front wall of a trailer. The socket usually has a plurality of male pins that mate with a plurality of female terminals in the plug. The male pins are typically soldered, welded or mechanically connected to the metallic ends of the wires in a sheathed cable. Likewise, the female terminals are soldered, welded, or mechanically connected to the metallic ends of another sheathed cable.
The basic structures of a jumper cable plug and its cooperating socket are the subject of SAE (Society of Automotive Engineers) standards, specifically SAE standard J560. The SAE standard J560 provides the minimum requirements for primary and auxiliary 7-pin jumper cable plugs and sockets (or, receptacle) for the tractor-trailer and converter dolly jumper cable systems. The standard also includes the test procedures, design and performance requirements. Standardizing the geometries of the socket and plug ensures that any trailer can be electrically connected to any tractor using any cable connection.
While the SAE standard J560 is popular in the U.S., the ISO (International Standardization Organization) has similar standards. For example, the ISO standard 1185 was developed in Europe for transferring electrical signals from a towing vehicle to a trailer through a 7-pin electrical connector. Other relevant ISO standards include, ISO standards 7638 and 12098. The SAE standard J560 and the ISO standards 1185, 7638, and 12098 are incorporated herein by reference.
The SAE and ISO standards only specify the minimum requirements for the connectors governed by their standards. In other words, particular connectors can differ from one another in features outside the SAE or ISO specifications.
Neither the SAE or ISO standards require that the plug and socket form a water-tight seal when connected. As a result, it has been found that the metallic connections in the plug and the socket remain exposed to moisture in the environment even when the plug and the socket are mated. Moisture enters into the socket cavity over time through the space between the mating plug and socket. If the moisture migrates to the mated male pins and female terminals, the moisture will cause the mated electrical terminals of the socket and plug to corrode, which overtime may degrade the electrical connection, or if severe enough, even cause a fault in one or more of the circuits of which the connection terminals are components. If the moisture that finds its way into the terminals of the mated plug and socket contain salt, such as the MgCl and/or NaCl salts used to de-ice roads during the winter season, the corrosion process is typically accelerated due to the presence of chloride ions.
Accordingly, there is a need for an improved jumper cable plug of the type used to electrically connect a jumper cable between a trailer and tractor, truck, or another trailer to establish an electrical connection between the two. More particularly, there is a need for an improved jumper cable plug with a moisture resistant seal that when mated to a cooperating socket provides improved moisture resistance to the electrical terminals of the plug and socket.